The present invention relates to oscillators and in particular to oscillators and methods for generating clock signals.
Oscillator circuits are found in many electronic circuit applications and are often used for generating clock signals that control the timing of circuits or control the logic state of a device. For example, oscillator circuits can be used in conjunction with circuits such as DC/DC converters, audio receivers, counters, shifting modules, microprocessors and FM (frequency modulation) circuitry.
Typically, charging and discharging of one or more capacitors primarily determines the frequency of the clock signal provided by an oscillator circuit. Such charging and discharging is often controlled by constant current sources or current mirrors supplying charge currents to the capacitors and the discharging is effected by controlling transistors coupled across the capacitors. However, prior art oscillators require a relatively large number of circuit components and therefore their power consumption requirements and silicon overhead may be unacceptable.